Merkel cell carcinoma and chronic arsenicism

Arsenic is a well-documented human carcinogen. Bowen's disease, squamous ce ll carcinoma, and basal cell carcinoma are the most common skin cancers fou nd in patients exposed to arsenic over the long term. Merkel cell carcinoma has been documented in Taiwanese patients who resided in an endemic area o f black foot disease, another condition found in patients with chronic arse nicism. We collected all cases of Merkel eel carcinoma diagnosed at two med ical centers in Taiwan (N = 11) to find a possible association between chro nic arsenicism and Merkel cell carcinoma. In our study 6 of the 11 patients were residents of the endemic areas for chronic arsenicism.